Technical Field
The present invention relates to a method for searching a power supply area, particularly to a method for searching a cross-regional power supply area based on a common information model (CIM) of a power grid, and further relates to a searching system used to implement the method, and belongs to the field of dispatching automation of a power grid.
Related Art
In commonly used methods for searching a power supply area at present, a network connectivity analysis and a power grid topology analysis for network path searching are mainly based. Generally, a power grid topological graph is searched by using a depth-first search algorithm and a width-first search algorithm. The depth-first search algorithm is a non-heuristic search, requires traversal on all nodes of a topological tree, and is a blind search algorithm. The width-first search algorithm is also a blind search algorithm. Different from the depth-first algorithm, the width-first algorithm starts from a root node, and traverses nodes of a topological tree along the width of the tree; and if a target is found, the calculation ends. The method for searching a power supply area by using the width-first search algorithm or the depth-first search algorithm requires traversal on and a search for a power grid model of the whole region, and with the gradual perfection of a power grid model, the power grid has an increasingly large structure and scale, so that a search by using a traversing method is increasingly time consuming, real situations of a power range cannot be displayed in real time, and on-site guidance requirements when an urgent fault occurs cannot be met.
In the Chinese patent application with the publication No. CN103544658A, a hash function is used in a power grid topological graph, and a topology hash table corresponding to various device types is created according to types of nodes and various devices and by using a device identification as a key and a device object as a value; and a topology network of the nodes is created for all the devices according to the created topology hash table corresponding to the various device types. However, with the unification and standardization of national power grid information, in order to make a device identification number unique in a whole power distribution network and facilitate further expansion of the scale of the power grid, the device identification number is generally set to a numerical value much greater than the number of elements in the power grid, and using the device identification as a key causes a waste of a large amount of storage space. In addition, the hash function is used to map a device identification to a key value in a hash table, so that a storage location in memory can be directly accessed according to the key value.
In this process, generally, a situation in which a same key value corresponds to multiple locations in the hash table occurs, and this situation is referred to as a collision; therefore, how to deal with a collision is an indispensible step in hash mapping. However, the patent application does not involve a method for dealing with a collision.
The Chinese patent application with the publication No. CN102957206A discloses a multi-granularity offline model splicing method oriented to a smart power grid. In the splicing method, for a boundary station, intranet nodes and devices inside the boundary station are reserved based on a device granularity, and extranet nodes and devices outside the boundary station are removed; and for a non-boundary station, a station granularity is reserved or removed according to intranet and extranet characteristics; therefore, a model splicing mechanism can be perfected, and an effect of model splicing can be effectively improved.